EPDM vs Silicone Rubber Compared for Industrial Use

EPDM vs Silicone Temperature Range

Silicone has a continuous service limit about 140°F higher than EPDM and stays flexible at slightly lower temperatures. The temperature range of silicone rubber extends from about minus 76°F to 446°F in continuous service, and specialized formulations tolerate short exposure near 572°F. Silicone also keeps its resistance to compression set at these temperatures, so a clamped gasket continues to seal through long production runs that would permanently flatten EPDM.

EPDM has a narrower range, with an upper limit that depends on how it was cured. Sulfur-cured grades are rated to about 250°F and peroxide-cured grades to about 302°F. Above those limits, EPDM hardens and loses sealing force gradually, often over several weeks of high-temperature service before a leak appears. At the low end, EPDM stays flexible down to about minus 58°F, which covers outdoor service in most North American climates.

Below 250°F. Any EPDM grade is rated for this range, so the choice depends on chemical exposure and cost.

From 250°F to 300°F. Peroxide-cured EPDM is rated for this range, but silicone leaves more margin for parts that cycle between high and low temperatures.

Above 300°F. Silicone is the better material for continuous dry heat.

Chemical Resistance of EPDM and Silicone

EPDM resists more water-based and polar chemicals than silicone does. Neither material, however, should be used in continuous contact with fuels or mineral oils. EPDM generally handles the following chemicals well.

• Hot water and steam to about 300°F, with specialty compounds rated higher
• Dilute acids and alkalis, including many cleaning agents
• Glycol-based brake fluids (DOT 3 and DOT 4) and phosphate-ester hydraulic fluids
• Polar solvents such as alcohols, ketones, and esters
• Silicone oils and greases

The main limitation of EPDM is petroleum. Mineral oils, greases, fuels, and hydrocarbon solvents cause it to swell quickly, which rules it out for lubricated or fuel-handling parts.

Silicone performs better than EPDM in hot dry air and has moderate resistance to some oils. It is weaker against acids, alkalis, and pressurized steam, and standard grades swell in fuels and hydrocarbon solvents much as EPDM does. Parts that handle fuel are usually made from fluorocarbon or fluorosilicone compounds instead.

Silicone vs EPDM Strength, Lifespan, and Cost

EPDM is stronger and less expensive at room temperature, while silicone keeps more of its strength and lasts longer at high temperatures.

Strength. At room temperature, the strongest EPDM compounds reach a tensile strength of about 2,500 psi, compared with roughly 1,500 psi for the strongest silicone. EPDM also resists tearing and abrasion better, which suits it to extruded seals and to parts that rub, flex, or press against sharp edges. Silicone loses less strength as temperatures rise, and above 300°F it becomes the stronger of the two.

Lifespan. Which material lasts longer depends on what wears the part out. EPDM usually lasts longer when abrasion, tearing, or steam is the main cause of wear, while silicone lasts longer when heat is.

Cost. Silicone costs more per pound and per sheet than EPDM. In high-temperature service, though, a silicone part that outlasts its EPDM equivalent can cost less over its service life. Comparing cost per cycle rather than cost per sheet shows which material is more economical for a specific application.

Read: How to Extend the Lifespan of Silicone Rubber Products

When to Use EPDM or Silicone

The most reliable way to choose between EPDM and silicone is to check four factors in order, starting with temperature because it rules out the most options.

1. Identify the peak service temperature, including process spikes and cleaning cycles, not only the normal operating temperature.
2. List every chemical the part will contact, from cleaning agents and steam to process resins and lubricants.
3. Assess the mechanical load, including abrasion, tearing, compression, and repeated stretching.
4. Compare cost per cycle of service life rather than cost per sheet or per gasket.

EPDM applications include outdoor seals, coolant and steam hoses, and sanitary gaskets in steam-cleaned food and pharmaceutical lines.

Silicone applications include high-temperature gaskets, oven and dryer door seals, food and medical parts exposed to heat, and forming membranes subject to repeated thermal cycling.

Why Membrane Presses Use Silicone Instead of EPDM

Most membrane presses use natural rubber or silicone membranes rather than EPDM. A press membrane has to stretch over every contour of a part and apply even pressure across the panel while absorbing the heat of each cycle. At moderate press temperatures, natural rubber does this better than EPDM because it stretches further and resists tearing. Above about 248°F, the upper limit for natural rubber, silicone is the standard choice. Between the two, they cover the full temperature range of most membrane presses.

In practice, natural rubber membranes are used for real wood veneer and deep contours, with a matte surface that reduces scuffing on high-gloss foils. Silicone membranes are used in 3D lamination, glass lamination, solar module production, and composite forming, where press temperatures run higher. Because the adhesive usually sets the press temperature, the membrane has to be matched to the adhesive as well as the heat.

Once silicone is chosen, the right silicone membrane sheet for vacuum pressing depends on its durometer, thickness, and surface finish. Softer grades conform to deep profiles, firmer grades suit flatter parts, and textured surfaces reduce scuffing and release more easily from 3D laminate.

Read: Silicone vs Rubber

Choose Smartech for the Right Membrane Material

A membrane that keeps its elongation and sealing performance over hundreds of press cycles reduces unplanned changeovers and downtime. At Smartech, we stock Steinbach silicone and rubber membranes in multiple grades, elongations, and surface finishes, with hundreds of membranes on hand for fast delivery. As the exclusive North American distributor for Steinbach AG, we have matched membranes to presses since 1998, looking at press temperature, adhesive, and part profile the way a process engineer would. That process helps customers get the right membrane on the first order instead of working through trial sheets.

Send us your press temperature, adhesive, and part profile for a membrane recommendation.

Frequently Asked Questions

Is EPDM Better Than Silicone?

Neither material is better for every application. EPDM costs less and performs better in water, steam, acids, alkalis, and outdoor service below about 300°F. Silicone is preferred for continuous dry heat above 300°F and for parts that must stay flexible through wide temperature swings.

What Are the Disadvantages of EPDM Rubber?

EPDM swells in contact with mineral oils, greases, fuels, and hydrocarbon solvents, making it unsuitable for lubricated or fuel-handling equipment. Its upper temperature limit is also lower than that of silicone, at about 250°F to 302°F depending on the cure system.

Is Silicone Stronger Than EPDM?

At room temperature, no. EPDM has higher tensile strength and better tear and abrasion resistance. Above 300°F, though, silicone keeps more of its strength and becomes the stronger material.

Are EPDM and Silicone Compatible?

Silicone oils and greases do not degrade EPDM and can be used to lubricate EPDM seals during assembly and maintenance. Petroleum-based greases make EPDM swell and should not be used on EPDM parts.

What Is EPDM Material Used For?

EPDM is used for roofing membranes, automotive weatherstripping, radiator hoses, brake system seals, pond and tank liners, and electrical insulation. Its low cost and resistance to weather, water, and steam make it the standard material for seals and sheet products used outdoors or in wet service.